Engine control systems may use various torque estimation methods (e.g., output from one or more torque sensors) in combination with various torque control methods (e.g., adaptive open-loop or closed-loop control methods) to provide reliable torque estimation and actuation. In particular, such control systems aim to improve torque accuracy by combining a reliable engine torque output measurement with an adaptive loop correction.
However the inventors herein have identified potential issues with such an approach. As one example, the engine torque measurements may not give enough information in the raw form to precisely correct the control system's characterization of the multiple degrees of freedom that affect engine torque. For example, an error between the torque produced by the engine and the torque commanded by the engine control system can be due to multiple factors such as injectors metering an incorrect amount of fuel, drift in mass airflow sensor measurements, thermal and mechanical losses in the system incurred due to age and/or other environmental factors, etc. Therefore, without knowing what is causing the difference between the commanded torque and the estimated torque, an appropriate correction may not be applied, and torque errors may remain. As such, data analysis methods may be applied to refine the raw engine torque information for more accurate torque correction. However, such analysis methods may be computation intensive. The processing power and memory required for such analysis methods may not be met by control systems currently configured on vehicles.
Some of the above issues may be at least partly addressed by a method of controlling a vehicle torque comprising, adjusting each data point of an engine torque data set with a slope and offset modifier from engine torque data on-board the vehicle, adjusting individual data points of the engine torque data set from engine torque data off-board the vehicle, and adjusting an engine operation based on the engine torque data set. In this way, engine torque data may be adjusted on-board the vehicle while the data is concurrently analyzed off-board for further torque accuracy.
In one example, an on-board vehicle control system may compute an on-board torque estimate based on torque inputs from various sensors on-board the vehicle and further based on adaptive torque adjustments. Therein, the vehicle control system may adjust an engine torque data set using a computation model that determines torque adjustment slopes and/or offset modifiers that are applied to all data points in the torque data set, en masse. That is, each and every data point of the data set may be adjusted in the same manner, with the same modifier. In parallel, the inputs from the various sensors and the on-board torque adjustments may be uploaded to an off-board control system, such as a cloud computing system communicatively coupled to the on-board control system, wherein the torque data may be analyzed in a more computation intensive manner using a computation model having a larger number of constraints and parameters. The off-board control system may adjust one or more individual data points independently. That is, only some of the data points of the data set may be adjusted, and the adjustments of the affected data points may be different from, and independent of each other. The off-board torque adjustments may be downloaded and combined with the on-board torque adjustments to provide more accurate torque control.
In this way, by performing some torque data processing on-board the vehicle using some parameters while performing additional torque data processing off-board the vehicle using additional parameters, a more reliable torque estimate may be achieved while maintaining the processing power and memory configuration of the on-board vehicle control system. By improving torque control, engine and vehicle performance may be improved.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.